The convicted killer at the center of the wildly popular investigative podcast "Serial" finally got his day in court today, after questions were raised about his guilt and whether he had a fair trial in Maryland 16 years ago.

Lawyers for Adnan Syed argued at a court hearing for a new trial, and called a key witness who was featured in the podcast but was never called to testify during Syed's original trial.

Asia McClain is a potential “alibi witness” who said she was with Syed at the public library near Baltimore’s Woodlawn High School at the time prosecutors previously said they believe his ex-girlfriend Hae Min Lee was murdered.

McClain, who goes by her married name now, Chapman, said she previously wrote to Syed twice to say she was with him that afternoon and that she was willing to speak up if needed. During her testimony today, she was asked why she is speaking out now.

"I felt it was the right thing to do. All the information needs to be on the table in the interest of telling the truth," she said today in court, sounding confident on the stand.

Brown had described McClain as a “big piece of the puzzle” at the beginning of the three-day, post-conviction hearing.

Syed's new defense team, led by Justin Brown, is arguing that Syed’s former lawyer, the late Cristina Gutierrez, failed to provide him with effective counsel during his 2000 trial and the cellphone tower evidence used by prosecutors was unreliable.

Syed, now 35, is serving a life sentence for Lee's death in 1999. Syed walked into court today wearing shackles and a blue jumpsuit, and sporting a long beard and a prayer cap.

Family, supporters and journalists were in attendance during the opening statements by the state and Syed’s defense team. “Serial” podcast creator Sarah Koenig, and former Baltimore Sun reporter, sat in the front row of the courtroom.

Syed and Lee were both students at Woodlawn High School. Lee went missing in January 1999, and was found weeks later, strangled and buried in Leakin Park, a few miles from the school.

The defense called two witnesses to the stand this morning, both of whom had worked with Gutierrez. Brown and his team say Gutierrez failed to provide Syed with effective counsel because of health issues, financial hardships and a family life in turmoil.

Phillip Dantes, who worked with and mentored Gutierrez, called her a “zealous” worker, but that she struggled with health issues, including multiple sclerosis. His testimony was largely denied because of numerous sustained objections from the state, who said the character-take down was a form of “smearing.”

The state also says Syed received a fair trial.

“He was convicted because he did it and the state proved it,” said Maryland Deputy Attorney General Thiruvendran Vignarajah, who is leading the charge against Syed.

The second witness, William Kanwisher, worked as an investigator for Gutierrez. During a somewhat testy testimony, Kanwisher called Gutierrez “accomplished,” but also says he noticed a lack of energy, and a decrease in focus from the lawyer because of her crumbling health.

“She became more erratic,” he said. “I had to do more of her cases,” going on to say that often times, Gutierrez would hand over entire cases for him to take on with just a handful of days to prepare. She died in 2004.

The post-conviction proceedings are meant to determine whether Syed will receive a new trial.

The Maryland Court of Special Appeals issued an order in May directing Syed’s case to a lower court so the testimony of McClain could be added to the record. After his conviction, McClain, another high school classmate, wrote him letters in jail, saying she had seen him in the library around the same time Lee was killed.

In November, Retired Circuit Court Judge Martin P. Welch granted Syed’s request to introduce the alibi witness testimony, as well as cell tower records that were later claimed to be unreliable, according to the carrier, saying it would “be in the interests of justice.” (It is not unusual for retired judges to hear cases).

“I don’t want to say it’s unusual, but he’s definitely beating the odds here,” said Becky Feldman, chief of the post-conviction defenders division at the Maryland Office of the Public Defender. “Filing motions to reopen a post-conviction are fairly common. We probably get hearings on motions to reopen on maybe 20 percent of the cases. Most of them are just denied.”

So what happens next?

“I would be shocked if we get a ruling on Friday,” Feldman said. “There’s no time requirement on when a court must issue a post-conviction ruling.”

Syed’s fate rests in the hands of Welch, who could issue an oral ruling on Friday, determining if Syed will get a new trial or not. The likelihood is that he will issue a written decision at a later time, which could take weeks to months. If Syed is granted a new trial, the state will likely appeal, Feldman says. Syed could be stuck in this process for months – even years, should the court take its time.